''Ophthalmothule'' (meaning "eye of the north"), was a cryptoclidid

plesiosaur The Plesiosauria or plesiosaurs are an Order (biology), order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period (geology), Period, possibly in the Rhaetian st ...

dating to the latest Volgian (around the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

boundary), found in the Slottsmøya Member

Lagerstätte A Fossil-Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. ''Konzentrat-Lagerstätten'' preserv ...

of the

Agardhfjellet Formation The Agardhfjellet Formation is a Formation (geology), geologic formation in Svalbard, Norway. It preserves fossils dating back to the Oxfordian (stage), Oxfordian to Berriasian stages, spanning the Late Jurassic-Early Cretaceous boundary. The for ...

Spitsbergen Spitsbergen (; formerly known as West Spitsbergen; Norwegian language, Norwegian: ''Vest Spitsbergen'' or ''Vestspitsbergen'' , also sometimes spelled Spitzbergen) is the largest and the only permanently populated island of the Svalbard archipel ...

. The type species is ''O. cryostea''.

Description

''Ophthalmothule'' was a medium-sized plesiosaur, measuring long. It was noted to have unusually large eye sockets, which suggests a paleobiological specialization, such as deep water and/or nocturnal hunting. Along with ''

Abyssosaurus ''Abyssosaurus'' ("bottomless lizard") is an extinct genus of cryptoclidid plesiosaur known from the Early Cretaceous of Chuvash Republic, western Russia. The type specimen, consisting of a fairly complete postcranial skeleton and parts of a sku ...

'', it is one of the youngest cryptoclidids known from

boreal Boreal, northern, of the north. Derived from the name of the god of the north wind from Ancient Greek civilisation, Boreas (god), Boreas. It may also refer to: Climatology and geography *Boreal (age), the first climatic phase of the Blytt-Sernand ...

regions. The holotype is known from skeletal material that includes a complete cranium and a partial mandible, a complete and articulated cervical vertebrae, a set of pectoral and anterior to middle dorsal series, and the pectoral girdle and anterior humeri.

References

Cryptoclididae Tithonian life Plesiosaurs of Europe Late Jurassic reptiles of Europe Jurassic Norway Fossils of Svalbard Agardhfjellet Formation Fossil taxa described in 2020 Sauropterygian genera {{Plesiosaur-stub